Category: Science & Technology

In seconds, Clay multiplies a pair of five-digit numbers and writes down the answer in a single line. There's none of the sloppy rows of zig-zagging numbers that would normally clutter a page. Such is the beauty of his homemade formula -- titled "How to Multiply Any Number by Any Number in Your Head" -- which is registered as TXu001325432 in the U.S. Copyright Office.

"There may not be anybody else in the world who knows how to do this but me," said Clay, 75, a retired pharmacist. "Zip, zip, zap and add 'em together."

You can reach Clay at This e-mail address is being protected from spambots. You need JavaScript enabled to view it. . He's available for class lectures, and his instruction book can be purchased for $33.

Clay worked out his system as a high school junior in Granville County, and aside from the Oxford High School math teacher who shrugged off his achievement, he never really showed it to anyone. Now, with his copyright, he'd like to demonstrate the ease of big-number arithmetic in classrooms, or even get it into math books. Send him $33, and he'll pass along a copy, postage paid.

"It's not complicated once you crack the code," he explained.

Clay's method is best explained on paper. Suffice it to say you multiply the digits on the right, cross-multiply and add the digits in the center, then multiply the digits on the left. Using that formula, you can work out 33 x 44 in about three seconds. It takes a little longer for Clay to figure 54,321 x 12,345, but when he tries it on a pocket calculator, the electronic number cruncher's screen is too puny. Advantage: human...MORE...

Read Full Story Here